In our previous discovery described in a patent application PCT/US06/22312 entitled “suspension culture vessels,” we had described a wide-body culture vessel with an inverted frusto-conical bottom on orbital shaker platform for suspension mammalian cell culture. Surprisingly, this system was significantly better than classical bioreactor and flat bottom shaker bottles. We had described this system making the culture medium climbing up onto the wall of the vessel easily with less hydro-mechanical stress. This system created a broad thin culture medium layer for extended surface, greater aeration and better mixing.
Interestingly, we did not know exact mechanism of action of this shaker-based frusto-conical bottom vessel system. In this invention, we have discovered the mechanism of action. Basing on the mechanism of action, namely a method to increase dissolved oxygen level in culture medium, we have designed and tested several types of mammalian cell culture bioreactors.